Virtual network addresses

ABSTRACT

Systems, methods and devices for virtual network addresses. A method comprises processing a request from a requestor to create a plurality of software network devices having a corresponding plurality of media access control (MAC) addresses. The MAC addresses may be allocated to a network interface circuit. The MAC addresses and the software network devices may be provided to the requestor. Incoming data units may be received from a network via a driver and a demultiplexor. Outgoing data units may be sent on to the network via a driver.

NOTICE OF COPYRIGHTS AND TRADE DRESS

[0001] A portion of this patent document contains material which issubject to copyright protection. This patent document may show and/ordescribe matter which is or may become trade dress of the owner. Thecopyright and trade dress owner has no objection to the reproduction byany one of the patent disclosure as it appears in the Patent andTrademark Office patent files or records, but otherwise reserves allcopyright and trade dress rights.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The invention relates to testing and analysis of communicationsnetworks, systems and devices, and, more specifically, to establishingand using virtual network addresses.

[0004] 2. Description of Related Art

[0005] Networks such as the Internet provide a variety of data of allkinds which is communicated using a variety of network devices includingservers, routers, hubs, switches, and other devices. Before placing anetwork into use, the network, including the network devices includedtherein are typically tested to ensure successful operation. Similarly,before placing a web site on the Internet, the web site and associatedservers and other network devices may be tested to ensure that theyfunction as intended and can withstand anticipated traffic demands.

[0006] To assist with the construction, installation and maintenance ofnetworks and web sites, networks may be augmented with network analyzingdevices, network monitoring devices, and network protocol conformancesystems, all are referred to herein as network testing systems. Thenetwork testing systems may allow for the sending, capturing andanalyzing of network communications.

[0007] One type of network testing system is the traffic generator.Traffic generators are used to originate simulated data on a live ortest network. Some traffic generators are loaded with traffic patterns,and the traffic generator originates data on the network according tothose patterns. Traffic generators may be used to test web sites andnetwork communications devices, for example.

[0008] As used herein, a network capable device is any device that hasthe ability to communicate over a network. In many networks, networkcapable devices each have a media access control (MAC) address toidentify the network capable device on the network. A computing deviceor other network capable device may include a network interface card(NIC) to access an Ethernet network. The NIC has a unique MAC address.

[0009] A MAC address is defined by industry standards as a hardwareaddress that uniquely identifies the network capable device. In Ethernetand IEEE 802 standards, the MAC address includes six octets totaling 48bits. The first three octets of the address are the manufacturer'sOrganizationally Unique Identifier (OUI). The OUI is assigned by theIEEE. The remaining three octets of the address uniquely identify thenetwork capable device and are referred to as the organizationallyunique address (OUA). The OUA is typically assigned by the manufacturerof the network capable device. MAC addresses are typically allocatedwhen the network capable device is manufactured and may be stored infirmware.

[0010] In current network testing systems and cards included in networktesting systems, each NIC has a single, unique MAC address.

DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a block diagram of an environment in accordance with theinvention.

[0012]FIG. 2 is a block diagram of a network card according to oneaspect of the invention.

[0013]FIG. 3 is a block diagram of a network card according to anotheraspect of the invention.

[0014]FIG. 4 is a flowchart of the actions taken to create multiplevirtual MAC addresses according to one aspect of the invention.

[0015]FIG. 5 is a flowchart of the actions taken to receive a data unitaddressed to one of the multiple virtual MAC addresses according to oneaspect of the invention.

[0016]FIG. 6 is a flowchart of the actions taken to send a data unitfrom one of the multiple virtual MAC addresses according to one aspectof the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Throughout this description, the embodiments and examples shownshould be considered as exemplars, rather than limitations on theapparatus and methods of the invention.

[0018] Systems of the Invention

[0019] Referring now to FIG. 1, there is shown a block diagram of anenvironment in accordance with the invention. The environment includes anetwork testing system 100, a network 140 and plural network capabledevices 150.

[0020] The network testing system 100 may include or be one or more of atraffic generator, a performance analyzer, a conformance validationsystem, a network analyzer, and/or a network management system. Thenetwork testing system 100 may include one or more network cards 120 anda back plane 110. Network testing system 100 may be in the form of acard rack, as shown in FIG. 1, or may be an integrated unit.Alternatively, the network testing system may comprise a number ofseparate units cooperating to provide traffic generation and othertasks. The network testing system 100 and the network cards 120 maysupport one or more well known standards or protocols such as, forexample, the 10 Gigabit Ethernet and Fibre Channel standards, maysupport proprietary protocols, and may support other protocols as wellas one or more varieties of the IEEE 802 Ethernet standards, such as,for example, IEEE 802.3 and IEEE 802.11.

[0021] The network cards 120 may include one or more field programmablegate arrays (FPGA), application specific integrated circuits (ASIC),programmable logic devices (PLD), programmable logic arrays (PLA),processors and other kinds of devices. In addition, the network cards120 may include software and firmware. The term network card encompassesline cards, test cards, analysis cards, network line cards, loadmodules, interface cards, network interface cards, data interface cards,packet engine cards, service cards, smart cards, switch cards, relayaccess cards, and others.

[0022] Each network card 120 may include one or more circuits, chips orchip sets that allow the network card 120 to serve as one or morenetwork capable devices. A network capable device is any device that maycommunicate over network 140. In one embodiment, each network card 120includes a circuit, chip or chipset and related hardware and softwarethat allows the network card 120 to communicate over a network. Thenetwork cards 120 may be connected to the network through wire, opticalfiber, wirelessly or otherwise. Each network card 120 may support asingle communications protocol, may support a number of relatedprotocols, or may support a number of unrelated protocols. The networkcards 120 may be permanently installed in the network testing system100, may be removable, or may be a combination thereof. As described inmore detail below, each network card 120 may provide one or more virtualMAC addresses in addition to or in place of a single traditional MACaddress. In this way each network card 120 may serve as more than onenode or client on the network. Each network card 120 may includemultiple MAC addresses and may emulate multiple virtual networkinterface cards (NICs) and/or multiple network capable devices.

[0023] The back plane 110 may serve as a bus or communications mediumfor the network cards 120. The back plane 110 may also provide power tothe network cards 120.

[0024] The network capable devices 150 may be any devices capable ofcommunicating over the network 140. The network capable devices 150 maybe computing devices such as workstations, personal computers, servers,portable computers, personal digital assistants (PDAs), computingtablets, and the like; peripheral devices such as printers, scanners,facsimile machines and the like; network capable storage devicesincluding disk drives such as network attached storage (NAS) and storagearea network (SAN) devices; networking devices such as routers, relays,firewalls, hubs, switches, bridges, and multiplexers. In addition, thenetwork capable devices 150 may include appliances such asrefrigerators, washing machines, and the like as well as residential orcommercial HVAC systems, alarm systems, telephones, and any other deviceor system capable of communicating over a network. The network capabledevices 150 may be referred to as devices under test (DUTs).

[0025] The network 140 may be a local area network (LAN), a wide areanetwork (WAN), a storage area network (SAN). The network 140 may bewired, wireless, or a combination of these, and may include or be theInternet. The network 140 may be public or private, and may be asegregated test network. Communications on the network 140 may takevarious forms, including frames, cells, datagrams, packets or otherunits of information, all of which are referred to herein as data units.The network testing system 100 and the network capable devices 150 maycommunicate simultaneously with one another, and there may be plurallogical communications links between the network testing system 100 anda given network capable device 150. The network 140 may be comprised ofnumerous nodes providing numerous physical and logical paths for data totravel.

[0026] Referring now to FIG. 2, there is shown a block diagram of anetwork card 210 according to one aspect of the invention. The networkcard 210 may be the network card 120 of FIG. 1. The network card 210includes a processor 212, a memory 216 and a network interface circuit218. The processor 212, memory 216 and network interface circuit 218 maybe included on a single chip such as a FPGA, or may be a combination ofmultiple chips or devices. The network interface circuit 218 may have aMAC management module 214 incorporated therein, or an FPGA having anetwork interface circuit 218 may a MAC management module incorporatedtherein. Alternatively, the MAC management module 214 may be included assoftware on a hard disk drive or other machine readable medium (e.g.,compact disk read-only memory, floppy disk) or flash memory device orother storage device (e.g. electronically erasable programmableread-only memory or EEPROM) which may be coupled to processor 212 and/ornetwork interface circuit 218 via a bus or other coupling technique.

[0027] Processor 212 may be coupled to memory 216 and network interfacecircuit 218. Processor 212 may be any processor or processing devicecapable of executing instructions. Instructions include object code,assembly code, high-level computer language instructions, and otherkinds of instructions. The instructions may be stored permanently ortemporarily on network card 210. From outside the network card, theprocessor 212 may receive instructions such as patterns of traffic whichthe network card is to generate. The processor 212 may have anapplication program interface (API) for external control of the networkcard 210. A user may use a software program on a host to enter commandswhich create the instructions that are sent to the processor 212. Theprocessor 212 may store the instructions in memory 216 before, after,and during their execution.

[0028] Memory 216 may be any memory device including random accessmemory (RAM). Additional memory devices may be included in network card210. Other kinds of memory devices, such as, for example, flash memoryand EEPROM, may be included in network card 210.

[0029] Network interface circuit 218 includes the software, firmware,and/or hardware that allows the network card 210 to communicate over anetwork via PHY 220. Network interface circuit 218 may be referred to asa port. There may be multiple ports on each network card 210. Eachport/network interface circuit 218 may support one or more protocolsthat conform to the data link layer (DLL) requirement of the OpenSystems Interconnection (OSI) reference model and/or the logical linkcontrol (LLC) and MAC layers of the IEEE 802 standards.

[0030] The MAC management module 214 may be software and/or firmwarethat allows multiple MAC addresses to be associated with the networkinterface circuit 218. An application program or other software program,module or subroutine may request that one or more MAC addresses beallocated to the network interface 218. This may be achieved by issuinga request to the MAC management module 214 of the network interfacecircuit via an API, by invoking a procedure call or subroutine, or byplacing data in memory or register location on the network interfacecircuit and invoking an interrupt. The MAC management module 214 maymaintain a MAC address table or other data structure to maintain a listof the MAC addresses allocated to and associated with the networkinterface 218. The MAC address table may be stored in memory 216, in amemory device on the FPGA, ASIC or other device on which the networkinterface circuit 218 is implemented.

[0031] The PHY 220 may be thick wire coaxial cable (such as RG-11), thinwire coaxial cable (such as RG-58), category (CAT) 3, 4 or 5 cable alsoknown as Unshielded Twisted Pair (UTP), wireless, and others. Thenetwork interface circuit 218 and the PHY 220 may support Ethernet, FastEthernet, Gigabit Ethernet, IEEE 802 and/or other communicationsstandards including, for example, without limitation, AsynchronousTransfer Mode (ATM), Fiber Distributed Data Interface (FDDI), tokenring, 1000BaseT, 100BaseT, 10BaseT, 10BaseF, 10Base2, 10Base5, andothers. Network 140 described above with regard to FIG. 1 also supportsone or more of these standards.

[0032] According to the systems and methods described herein, networkinterface 218 may generate outgoing data units 230 from multiple MACaddresses over PHY 220. Network interface circuit 218 may receiveincoming data units 240 addressed to multiple MAC addresses over PHY220.

[0033] Referring now to FIG. 3, there is shown a block diagram ofnetwork card 300 according to one aspect of the invention. The networkcard 300 may be the network card 120 of FIG. 1. Network card 300 mayreceive incoming data units and transmit outgoing data units over PHY350. Network card 300 includes a media access control layer driver 340which allows for communication over the particular kind of physicallayer that is PHY 350. For example, driver 340 may support communicationover one or more of coaxial cable, thin wire coaxial cable, CAT-5cable/UTP, wireless, and others.

[0034] Demultiplexor 330 is included in network card 330. Demultiplexor330 is virtually or logically coupled 342 to driver 340. Demultiplexor330 receives incoming data units from driver 340. The incoming dataunits may be addressed to one or more MAC addresses. Demultiplexor 330is logically or virtually coupled 332 to software network devices 320.Demultiplexor 330 passes or makes available incoming data unitsassociated with each of different MAC addresses to each of the softwarenetwork devices 320.

[0035] Software network devices 320 are devices created according to theLinux operating system 310 or other operating system. In Linux orversions of the Unix operating system an IOCTL call may be used tocreate/access the software network devices. Each of the software networkdevices 320 is associated with a different MAC address.

[0036] Driver 340 binds or maps each MAC address to a correspondingsoftware network device. Driver 340 may maintain MAC address table inthe form of a database, list or other data structure associating MACaddresses with network devices. This MAC address list may be accessedwhen an IOCTL, API or other subroutine or procedure is used to accessand/or create a MAC address/network software device.

[0037] Software network devices 320 pass or make available incoming dataunits to network layer, session layer, presentation layer, andapplication layer software programs via the Linux operating system 310.The session layer and/or network layer software programs may be includedin the Linux operating system 310. The network layer included in theLinux operating system may support, for example, the transmissioncontrol protocol (TCP), the internet protocol (IP), the user datagramprotocol (UDP) protocols and/or other protocols. Sockets or other APIprovided by an operating system such as Linux 310 may be used by upperlayers and application programs 302 to access the software networkdevices 320. In this way, application programs and other upper layersoftware may access the software network devices 320 having the virtualMAC addresses in the same manner as the application programs accesstraditional network devices.

[0038] Outgoing data units from each of different MAC addresses may becreated and sent based on instructions received from an applicationlayer program 302 external to the network card 300 and above the Linuxoperating system 310. In other embodiments, the application program 302may be included in the network card, and/or multiple applicationprograms 302 may be included both external to the network card 300 andin the network card 300. The application program 302 may specify thatdata units be sent from a particular source MAC address by accessing theappropriate software network device 320. Software network devices 320receive information and/or instructions to create and/or send data unitsfrom one or more application programs 302 or other upper layer programsvia the Linux operating system 310. Each of software network devices 320is logically or virtually coupled 322 to driver 340. Outgoing data unitsinitiated by a network layer program, an application program or otherupper layer program are transmitted by a network device 320 via driver340 over PHY 350.

[0039] As set forth in the preceding paragraphs, the software networkdevices 320, in combination with supporting components, may each serveas a virtual NIC and/or network node. In this way, an applicationprogram may use a single network card to emulate multiple virtual NICs,each having a distinct MAC address. The MAC addresses may be createdrandomly and/or sequentially. The MAC addresses may include the deviceor system manufacturer's Organizationally Unique Identifier (OUI) and asequentially or randomly selected organizationally unique address (OUA).The testing system may allow a user to select OUIs and OUAs manually.The testing system may allow a user to select whether the OUI and/or theOUA should be created randomly or sequentially.

[0040] Methods of the Invention

[0041] Referring now to FIG. 4, there is shown a flowchart of theactions taken to create multiple virtual MAC addresses according to oneaspect of the invention. A request to create a number of virtual MACaddresses is received, as shown in block 410. This request may be madeby an application program such as a network testing program, a networktraffic generating program, and others. This request may be made byusing a procedure call, may be achieved by placing data in registers ofa processor and invoking an interrupt, and by other techniques. Therequest may specify to create one or more software network deviceshaving a specified MAC address, a random MAC address, or a partiallyspecified and partially random MAC address. The network testing programor other application may designate specific MAC addresses or portionsthereof, may specify numerical boundaries within which the MAC addressesshould be randomly and/or sequentially created, and/or may request thatone or more OUIs and the OUAs of the MAC addresses be randomly and/orsequentially created.

[0042] The requested number of virtual MAC addresses is created, asshown in block 420. A software network device for each of the virtualMAC addresses may be created, as shown in block 430. This may beachieved using Linux device creation techniques, such as, for example,an IOCTL call. A MAC address table that lists the MAC addresses andcorresponding software network devices is updated, as shown in block440.

[0043] The virtual MAC addresses and the corresponding software networkdevices are returned or made available, as shown in block 450. This maybe achieved by passing a pointer to the software network device that isrecognizable by the operating system, returning an identifier of thesoftware network device that is recognized by the operating system, andby other techniques. The identifier may be a text string, a number, acombination thereof, or any identifier.

[0044] Referring now to FIG. 5, there is shown a flowchart of theactions taken to receive a data unit addressed to one of the multiplevirtual MAC addresses according to one aspect of the invention. A dataunit addressed to one of the virtual MAC addresses associated with anetwork card may be received from a network over the PHY, as shown inblock 510. A MAC address table may referenced to identify acorresponding software network device, as shown in block 520. The dataunit may be passed to the software network device associated with thevirtual MAC addresses specified in the data unit, as shown in block 530.The data unit is made accessible to application programs via thesoftware network device, as shown in block 540. The data unit may thenbe accessed by an application program via an IOCTL call to the softwarenetwork device, a socket, pending on a queue associated with thesoftware network device, an API, or other techniques.

[0045] Referring now to FIG. 6, there is shown a flowchart of theactions taken to send a data unit from one of the multiple virtual MACaddresses according to one aspect of the invention. An applicationprogram prepares a request to send a data unit by accessing a softwarenetwork device, as shown in block 610. This may be achieved by using aLinux interface to the software network device via a procedure call. Theprocedure call may provide access to a socket or other API associatedwith the software network device. This may also be achieved by placingdata in registers of a processor and invoking an interrupt, and by othertechniques. A software network device receives the request to send adata unit from the software network device to a destination address, asshown in block 620. A data unit addressed from the virtual MAC addressassociated with software network device is prepared, as shown in block630. The data unit is sent onto the network via a driver, as shown inblock 620.

[0046] According to the methods described in FIGS. 4, 5 and 6, anapplication program and/or a user may access the multiple MAC addressesof a single network card to receive, emulate and/or generate a pluralityof data units to evaluate the performance of one or more DUTs. In thisway, a single network card employing the methods described herein mayreplace multiple traditional hardware NICs.

[0047] Although exemplary embodiments of the invention have been shownand described, it will be apparent to those having ordinary skill in theart that a number of changes, modifications, or alterations to theinvention as described herein may be made, none of which depart from thespirit of the invention. All such changes, modifications and alterationsshould therefore be seen as within the scope of the invention.

It is claimed:
 1. A network card comprising: a processor a memorycoupled to the processor a network interface circuit coupled to theprocessor and the memory, the network interface circuit for coupling toa physical layer of a network instructions which when executed by theprocessor cause the processor to perform operations including allocatinga plurality of media access control (MAC) addresses to the networkinterface circuit.
 2. The network card of claim 1 having furtherinstructions which cause the processor to perform actions comprising:receiving over the network a data unit addressed to one of the virtualMAC addresses associated with the network card.
 3. The network card ofclaim 1 further comprising a software network device for each of theplurality of MAC addresses.
 4. The network card of claim 3 wherein thesoftware network device comprises an identifier recognizable by anoperating system as referring to a particular virtual network device. 5.The network card of claim 3 wherein the software network devicecomprises a virtual network device recognized by an operating system andidentified by an identifier.
 6. The network card of claim 2 furthercomprising a software network device for each of the plurality of MACaddresses, and the receiving operation further comprises passing thedata unit to that software network device associated with the MACaddress specified in the data unit.
 7. The network card of claim 1having further instructions which cause the processor to perform actionscomprising: receiving a request to send an outgoing data unit from aspecified MAC address of the plurality of MAC addresses to a destinationaddress transmitting over the network the outgoing data unit to thespecified MAC address.
 8. The network card of claim 7 further comprisinga software network device for each of the plurality of MAC addresses,and the receiving operation comprises receiving via a software networkdevice associated with the specified MAC address the request to send theoutgoing data unit.
 9. A network testing, system comprising the networkcard of claim
 1. 10. A network having a network testing system thatincludes at least one network card of claim
 1. 11. A method comprising:providing a network card allocating a plurality of media access control(MAC) addresses to the network card.
 12. The method of claim 11 furthercomprising: creating a software network device for each of the pluralityof MAC addresses.
 13. The method of claim 11 further comprising:receiving over the network a data unit addressed to one of the MACaddresses associated with the network card.
 14. The method of claim 13further comprising creating a software network device for andcorresponding to each of the plurality of MAC addresses, and thereceiving step further comprises passing the data unit to that softwarenetwork device corresponding to the MAC address specified in the dataunit.
 15. The method of claim 11 further comprising: receiving a requestto send an outgoing data unit from a specified MAC address of theplurality of MAC addresses to a destination address transmitting theoutgoing data unit over the network to the specified MAC address. 16.The method of claim 15 further comprising creating a software networkdevice for each of the plurality of MAC addresses, and the receivingstep comprises receiving via the software network device associated withthe specified MAC address the request to send the outgoing data unit.17. A network card comprising: a driver to send data units onto andreceive data units from a network a plurality of software networkdevices each having a corresponding media access control (MAC) address,the software network devices to send outgoing data units onto thenetwork using the driver, the software network devices specifying thecorresponding MAC addresses as source addresses a demultiplexor toreceive incoming data units from the driver and to distribute theincoming data units to software network devices corresponding todestination addresses specified in the incoming data unit.
 18. Thenetwork card of claim 17 further comprising: an operating system throughwhich one or more application programs may access the network devices tosend data units and to receive data units.
 19. The network card of claim18 wherein the application program resides on the network card.
 20. Thenetwork card of claim 17 wherein the network is an Ethernet network. 21.The network card of claim 17 further comprising a processor and amemory.
 22. A network card comprising: a driver to send data units ontoand receive data units from a network a demultiplexor to receiveincoming data units from the driver and to distribute the incoming dataunits to a plurality of software network devices corresponding todestination addresses specified in the incoming data unit the pluralityof software network devices each having a corresponding media accesscontrol (MAC) address, the software network devices to send outgoingdata units onto the network using the driver, the software networkdevices specifying the corresponding MAC addresses as source addresses,the software network devices receiving incoming data units from thedemultiplexor.
 23. A method comprising: processing a request from arequestor to create a plurality of software network devices having acorresponding plurality of media access control (MAC) addressesallocating the plurality of MAC addresses to a network interface circuitproviding to the requestor the plurality of MAC addresses and theplurality of software network devices.
 24. The method of claim 23wherein the request includes a number of software network devices to becreated, a designation whether the MAC addresses are requestor providedor should be generated.
 25. The method of claim 24 wherein the MACaddresses include an organizationally unique identifier (OUI) and anorganizationally unique address (OUA), and the designation includeswhether the OUI is requestor provided or should be generated, andwhether the OUA is requestor provided or should be generated.
 26. Themethod of claim 24 wherein the designation includes whether the MACaddresses should be randomly or sequentially generated.
 27. The methodof claim 23 further comprising: receiving over the network incoming dataunits addressed to the MAC addresses allocated to the network interfacecircuit passing the incoming data units to software network devicescorresponding to destination MAC addresses specified in the incomingdata units.
 28. The method of claim 23 further comprising: receiving viathe software network devices requests to send outgoing data units to oneor more destination address from one or more MAC addresses correspondingto the software network devices transmitting the outgoing data unitsover the network to the destination addresses.
 29. The method of claim23 wherein the allocating further comprises: updating a MAC addresstable that includes a list of MAC addresses and corresponding networksoftware device identifiers.
 30. The method of claim 27 wherein thepassing further comprises referring to a MAC address table to determinewhich software network devices correspond to the destination MACaddresses specified in the incoming data units.
 31. The method of claim27 wherein the receiving is achieved using a socket interface providedby an operating system.
 32. The method of claim 28 wherein thetransmitting further comprises referring to a MAC address table todetermine which destination MAC addresses correspond to the softwarenetwork devices that received the requests.